Solar energy can be used for heating and/or cooling of interior spaces in buildings. For example, photovoltaic solar panels may be used to convert sunlight into electrical energy that can be used to operate a compressor of a cooling system. However, solar energy is not available at a consistent level and a dual system that is operated using both a solar and a conventional energy source has been proposed.
However, it would be advantageous if the efficiency of such a dual system could be further improved.